Television apparatus



July 14, 1931.

L.. o-sKow 1,814,181

TELEVISION APPARATUS Filed Nov. 8, 1928 7 sheets-sheet 1 I ll'lIl lawINVENTOR ATTORNEY July 14, 1931. l.. osKow i 1,814,181

TELEVISION APPARATUS l Filed Nov. 8v lzs 7 sheets-sheet 2 ATTORNEY July14, 1931. l.. osKow TELEVISION APPARATUS Filed Nov. s, 1928 7sheets-sheet 5 /f4 ATTO EY' July 14, 1931. o`sKow TELEVISION APPARATUSFiled Nov. 8. 1928 7 Sheets-Sheet 4 o u/s 0.517044 NVENTOR Bv 4 IATTRNEY July 14, 1931. 1 osKow TELEVISION APPARATUS Filed Nov. 8, 1928 7Sheetsheet 5 July 14, 1931. osKw TELEVISION APPARATUS Filed Nov. f1,v1928 7 sheets-sheet e iNvENToR acl/5 ffon/ July i4, 1931. L osKow1,814,181

` TELEVISION APPARATUS Filed NOV. 8, 1928 7 Sheecs-Shee 7 ou, 3 @StroblNVENTOR FIG.7

/ATTORN EY Patented `ul'y 1.4', 193

PTSEN'FI FFIC LOUIS OSKOW, BROOKLYN, NEW YORK, ASSIGNOR OF ONE-HALF 'lvOMORRIS KIRSCHSTEIN, OF NEW YORK, N. Y.

TELEVISION APPARATUS Application filed November s, 1928.y serial No.317,911.

This invention relates to television. One object of the invention is toprovide a scanning means and method whereby edective scanning may be hadfor large areas and at great frequencies with apparatus of very compactconstruction having comparatively smallk moving parts that may bereadily assembled into a neat and compact unit.

A further object of the invention is to provide a scanning means andmethod having simple means for varying` the size of the beam of lightincident upon the subject to be scanned.

A still further object of the invention is to n be obvious and parthereinafter pointed out.

The invention accordingly consists in the features yof construction,combinati-ons of elements, and arrangement of parts which will beexemplified in 4the construction herein- 35 after described, and ofwhich the scope of application will be indicated in the followingclaims. ,l

In the accompanyingdrawings, in which is shown one ofthe variouspossible illustra- 40 tive embodiments of this invention.

Fig. 1 is a generally diagrammatic view of the apparatus and electricalsystem embodying the invention as applied to conductor wirestransmission;

Fig. 2 is a front view of the sending apparatus with parts broken away;

Fig. 3 is a partial cross-sectional view taken on line 33 of Fig. 2;

. Fig. A is across sectional view taken on *5G line 4 4 of Fig. 2;

Fig. 5 is a front View of the receiving apparatus;

Fig. 6 is a cross-sectional view taken on line 6 6 of Fig. 5;

Fig. 7 is a partial cross-sectional view taken V55j on line 7-7 of Fig.5; Fig. 8 is a side view of the shutter with parts broken away, and; l

Fig. 9 is an exaggerated view showing the shutter slit, and thelaminated member in sev- 60 eral relative positions.

Referring in detail to the drawing, Fig.'1 diagramm'atically showsthesystem and apparatus embodying the invention. As seen in said figure,the system comprises a send- 65 ing station A and a receiving station B.The sending vstation A generally comprises a scanning device 10consistingofa screen 11, illuminating means 12 and a shutter 13, anddevice 14- to operate said shutterA 13. 70

Said device 14e Vincludes an electro-magnet 15 having a coil 16connected at one end 17,

.thru a make-and-break switch 18, to a wire 18a leading to the receivingstation B. The opposite end 19 of said coil 16 is connected 75 thru avariable resistance 20 to one lead 21 of a source of electric power 22.'The secondV lead 23 of said power supply22is grounded Vas at 24.

At the sending station A, a photoelectric cell 25 is associated with thescanning device in a manner hereinafter described in detail. Said cell25 is preferably connected' to an amplifying outfit 26 thru conductorwires 27, 28, one of said wires 27 being grounded g5 as at 29 beyond theamplifying station. The other wire 2 8 leads to the receiving station B.

The receiving station B is likewise provided with a scanning device 10a,substantiallylsimilar to scanning device 10 at the sending station,`andcomprises a screen 11a; and shutter 13a. The illuminating means forthescanning device 10o: comprises a neon tube 30 connected at one terminalto said a5 conductor 28 coming from the sending station A. The otherterminal of said tube is grounded as at 31; Y

The shutter 13a is actuated by an electromagnetic device 14@ providedwitha coil 16a. loo

shown). may be secured to the inner surface of wall One end 17a of saidcoil 16a is connected to said conductor wire 18a leading from thesending station. The other end 19a of said coil is grounded as at 24a, avariable resistance a being interposed in said wire 19a. An electricpower source 32 connected to the amplification outfit 26 supplies thecur- .rent to the conductors 27, 28, photoelectric cell 25, and neontube 30, the circuit thru said devices being completed by said grounds29, 31. Y

Proceeding now to a detailed description of the apparatus, the apparatusof thesend-V ing station A is shown in Figs. 2, 3 and 4 to be mounted ona base plate 40 having a pair of spaced L-shaped supports 41 securedthereto. Each of said supports. comprises a foot portion 42 attached tosaid base, as by studs 42a, and nuts 425, and a vertical upstanding leg43 extending upwardly from said foot portion. Secured to .saidl legs 43in any suitable manner, is a lamp casing 44 comprising a bottom wall45soniewhat spaced above base 45, a top wall 46 and a substantiallycylindrical side wall 47 received within flanges a, 46a extendinginwardly from said bottom and top walls respectively. Said wall 47terminates in flat aligned vportions 48, secured in any suitable mannerto said legs 43. The lamp casing 44 may be further supported on base 40by studs 42a extending thru suitable openings in said bottom wall 45 andnuts 49 screwed on said studs at each side of said bottom wall. The topwall 47, and the flange 46aj thereof provided with bent openings 465 topermit circulation of air to the interior of the casing.

An electric bulb 50 for providing light for the scanning device, may bemounted on' the bottom wall 45, the base 51 of said lamp extending thrusaid bottoni wall 45 to 1eX- pose the terminals thereof for connectionto any suitable source of electric` power (not A number of similarmirrors 52 47 for reflecting the light from bulb 50 thru the space 7 5between portions 48 of the casing to the screen 11 and shutter 13 of thescanning mechanism 10.

Said screen and shutter are supported in arms 55, 56 extending from eachof legs 43. To this end said arms 55 are formed with an aligneddove-tailed groove 57. A frame member 58 may be suspended from said arms55 by dove-tailed portion 59 engaging said groove 57 A second framemember 60 substantially symmetrical to said trame 58 may be secured tosaid frame 58 at one end thereof by connecting member 61 and studs 62.Said studs extend thru suitable threaded openings 63 in said connectingmember 61 and threaded openings 64 in lugs 65 eX- tending from saidtrame members 58, 60.

i Lock nuts 66 may be provided for locking Thin plates 70 are interposedbetween the strips at each end to form a number of narrow slots 71between said strips. A heavy end plate 72 may be interposed between thelaminated member 68 and the studs 62 to allow for tightening the strips69 and plates 7 O against the end wall 67 in assembling the parts of thescreenl The strips 69, are of greater width than the slots 71 which arevery narrow. Y

Means is provided for moving the entire screen ll longitudinally toadjust the positions 76 receiving a rod 77. A worm gear 7 8 is fixedlymounted on said rod 77 between said bearings 76, said rod extendingbeyond one of the bearings 76, and terminating in a finger head 79 forrotating the rod. The under portion or" frame member 58 is formed with aracked surface 80 ,for cooperating with the worm gear 78. Rotation ofsaid rod obviously. will move the screen 1l to the right or leftdepending upon the direction of rotation.v The arms 56 support the wormgear 78, and thus aid in supporting the screen 1l in proper position.

vaid trames 58, 60 are also provided with means for slidably supportingthe shutter 13.V Said means comprises a longitudinal eXten sion 81projecting from frame 58, formed with a groove 82 inthe under facethereof. The lower frame 60 is provided with a longitudinal extension 83provided with a V- shaped groove 84 receiving ball bearings 85.

A plate 86 may be secured at its upper edge portion to a plate 86ahaving a portion 87 receivable in said groove 82. At its lowerv edge,-said plate 86 is secured to a plate 88 having a V-shaped groove 89 inits lower face, complementary to groove 84, and also receiving said ballbearings with a vertical rectangular elongated opening 90 substantiallythe height of the slots 71 in screen 11.

A plate 91 may be secured to said plate 86, in spaced relation thereto,by a ZV-shaped braclreth92 at one end and by a stud 93 at the other.Said bracket 92`is provided with a foot portion 94 secured to said plate86 as bya small bolt 95, and with a foot portion 96 secured to plate91,'as by a studor pin 97 and lock nuts 98. @ne end 100 of a connectingrod 101, the function of which will appear hereinafter, is looselyreceived on the .stud

ioo

93 between apair of nuts 102. A nut 103 screwed on said stud 93 clampsthe plate 86 to an adjacent nut 102. Said plate 91 is positioned closeto screen 11 and is provided with an opening 104 similar to and alignedwith opening in plate 86.

l An adjustable shutter member 105 may be pivotally mounted with respectto plate 86. Said member 105 comprises a plate 106 pivotally mounted onstud 97 between plate 91 and an adjacent nut 98. Said plate 106 isprovided with a pair of spaced outstanding lugs 107. A plate 108substantially symmetrical to plate 106 and provided with spacedoutstanding lugs 109, -is adjustably secured to said plate 106 in the-sameplane therewith. To effect this adjustable attachment, studs 110are secured to lugs 109 and extend thru suitable apertures in lugs 107.Said studs are secured to lugs 107, 109 by a pair of lock nuts 111 toeiiect the adjustment in the well known manner. Said plates 106, 108 areprovided with adjacent knife edges 1060, 108@l respectively,substantially in alignment with openings 90, 104. Adjustment of locknuts 111 will vary the width of the slit 112 between the knife edges.The shutter may be adjusted to member 105 in various angular positions.To this end a Z- shaped member 112 is rigidly secured at one arm 113 toplate 91, preferably by clamping saidarm to said plate by the nut 102adjacent said plate 91, the opposite arm 114 of said member 112 beingprovided with a screw threaded opening 115 receiving, a small screw 116,having a pointed end 117 extending into a circular groove 118 formed inplate 109. The groove 118 forms only a small arc since only a limitedadjustment is necessary. Said'arc is formed in a radius equal to thedistance between the pointed end 117 of screw 116 and the stud 97 aboutwhich shutter member 105 is pivoted. The screw 116 may be loosened topermit the pivoted :r movement and tightened to lix the member 105 inany adjusted position to bring the sli-t' at its lower end 124 to lug125, secured to the base 40. The electro-magnetic device 15 foractuating the cross-arm 123 includes the coil 16 housed in a box 126mounted on said base 40. A metallic core 127 slidably fits in said 'fcoil 16 in the well known manner, and its core is connected to a rod128, which in turn is pivotally connected to stud 129 to said crank arm123 a short distance above the lower end 124 thereof. The stud 129 mayengage a small slot 129er in said arm 123 to-permit `reciprocation oflrod 128 lin a horizontal plane. When the coil 16 is-energized the coreis 4magnetically attracted to the left, as seen in Fig. 2, thus rotatingthe arm 123 about its 'lower end, moving shutter 13 to the left. rllheshutter obviously will move a greater distance than does the core 127,due to the relative lengths of arm 123 and the portion thereof belowstud 129.

The make-and-break switch mechanism 18 is provided for automaticallydeenergizing and energizing the coil 16 to produce a regular periodicreciprocation of the shutter 13 over a uniform distance. Said `mechanismcomprises a U-shaped member 130 adjustably secu-red to rod 128 as by aset screw 131, and provided with parallel arms 132, 1.33. The latter areadjusted to move in the path .of a lug 134 secured to a rod 135l whichis mounted in spaced bearing members 1136 for sliding movement parallelto rod 128. Said rod 135 is provided with stop 137 to limit thereciprocatory movement of said rod. One end portion 138 of said rod 135is received in a recess 139 formed in a small plate member 140yieldingly secured to said end portion 138, as .by la stud 141 andspring 142. Said stud 141 is secured to said end portion 138 and extendsthru an opening in member V140. The spring 142 is interposed betweensaid plate 140 and the head 143 of said screw 141. Said plate terminatesin a blade 144 adapted to engage an electrical contact member 145,attached to terminal 146 by a jumper 147. Said terminal 146 connects toone end 17 of the coil 16. It will now be apparentthat when coil 16 isenergized and core 127 moves to the left (Fig. 2) the circuit thru thecoil will remain closed until arm 133 of member 130 engages the lug 134,to'move rod 135. This movement will break the contact 144, to open thecircuit and deenergize the coil.

Means is provided for moving the core to the right automatically uponsuch deenergization of said coil 16. Said means comprises a tensionspring 150 connected at one end to a lug 151 extending from said core127. The opposite end 152 of said spring is adjust-ably .connected thruVa screw153 to an upstanding arm 154 supported on said base 40. Saidspring 150 is tensioned when the core 127 is moved to the left. Uponbreaking the contact at the snap switch 144, 145, the tension in saidspring retracts the core 127 and consequently the rod 128 and the member130. Vhen arm 132 of said member 130 strikes lug 134, rod 135 will bemoved to the right and plate 144 will engage contact 145 to againcomplete the circuit. This cycle of operation is continuous.

Shock absorbing means is provided for the rod 128. For this purpose, theupstanding arm 154 is provided with a slotted portion 155 straddlingsaid rod 128. A pair of collars V156, 157 are loosely ymounted onsaidrod von i dit() bothsides of arms 154, and collar 158 is fixed to rod128 adjacent the stud 129. A compression spring 160 is interposedbetween collar 157 and collar 158, and another com-` pression spring 161similar to spring 160 is mounted on said rod 128 between member 130 andcollar 156. Movement of the rod 128 to the right and left will be easedby springs 160, 161 when portion 155 of arm 154 strikes said collars156, 157.

As above described, one end of coil 16 connects to said binding post146. The opposite end 19 of said coil 16 is connected to a binding post170, and a lead 171 connects said binding post to one end of rheostat 20which is mounted on the front face 172 of the boX 126. The rotatingcontact arm 173 for said rheostat is connected thru lead21 to oneContact 174 of a switch 176 connected to the power source 22. The othercontact 175 of said switch is connected to said power source 22 which isprovided with a lead 23 grounded at 24 as show in the wiring diagram inFig. 1. Y

The circuit thru the coil 16 connects to the receiving station B thrulead 18a. The connection for said lead 18a at the sending stationcomprises a spring arm having sliding contact with rod 135. Said arm 180may be secured to base 40 as at 181. t vwill be understood that as thecircuit thru the coil 16, completed and bro-ken, so will the entirecircuit, including` theY conductor 18a be completed and broken.'

The receiving apparatus'shown in detail inFigs. 5, 6 and 7 is mounted ona base 40a. Said apparatus is similar in most respects to the sendingapparatus described above, and comprises a lamp casing 47a, a screen11a, and the shutter 13a all similar to casing 47, screen 11 and shutter13. A detailed description of these parts of the receiving station andalso ofthe electro-magnetic actuating device 14a is therefore notnecessary in view of the full description of the sending station, andonly the diiferences in the structure will be described.

The receiving station B is not provided with any make and breakmechanism for the coil 160;, since the circuit thru said coil iscont-rolled at the sending station. One end 17 a, of coil 16a isconnected to the binding post 186 to which the conductor 18a coming fromthe sending station is connected. The coil 16a is in the same circuit ascoil 16 and thus the core 127C@ is actuated in synchronism (for apurpose hereinafter appearing) with core 127. A retracting spring 150@is provided for said core 127er.. The opposite end 19a of coil 16a isconnected to terminal 187 of the rheostat 20a. The rotating contact arm173@ for said rheostat is connected by a lead 21a to one contact 174'@of a switch 176a. The other contact175a of said switch is grounded inany suitable manner as shown at 24a in Fig. 1.

. It will be noted that the illuminant for the casing 47 ais a neon tube30. One terminal 188 of said tube is grounded in anyv suitable manner asshown at 31 in Fig. 1.

The other terminal 189 for said neon tube extends to an ordinaryamplification outfit 26. This outit may comprise the usual amplificationset and therefore no detail showing of the same is included. Theamplification outt may be connected by wires 27, 28 to a photoelectriccell 25 which may be mounted on the cover 46 of casing 47. The cell 25is preferably mounted for universal adjustment. To this end the base 190of said cell is mounted on a U-shaped bracket 191 having arms 192pivotally lmounted on Va pin 193, extending thru arms 194 of a U-shapedmember 195. A wing nut 196 screwed on pin 193 tightens the cell 25 inany desired adjusted position in' a plane transverse to said pin 193.Said bracket 195 is provided with a depending threaded portion 197extending thru an opening 198 in said cover 46. Said portion 197receives a nut 1986i. A spring washer 199 may be interposed between saidnut 198e/I and the under surface of said cover 46. This constructionpermits rotation of said brackets 195, sw'

station B is provided with a lens 201 mounted in an annular socket 202formed integrally with frames 58B, 60B mounting the screen 11a.

The receiving station B is further provided with screen means for theimages transmitted thereto from the sending station A. For this purpose,a pair of spaced parallel walls 205 eXte-nd upwardly from arm 550integrally formed with supporting legs 43a. Said walls 205 are providedwith aligned apertures 206 centrally located with respect to said screen11a. VThe smooth end 207 of a screw threaded shaft 208 is received insaid openings 206. Collars209 may be secured to said shaft 207 as by setscrews 210 adjacent said walls 205 to prevent longitudinal movement ofshaft 208 in either direction.

Said walls 205 are further provided with a pair of aligned openings ateach end thereof for similarly mount-ing the end portions of guide rods216 in spaced parallel relation to shaft 208 Von each side thereof. Ascreen member 214 ismounted on said shaft 208 and rods 216 for`longitudinal adjustment with respect to the scanning assaggi devicelOa.Said member 214 comprises Ia frame 213 provided with an upstandinginternally screw threaded boss212 adapted to coact with the threads ofshaft 208. .Said frame. is further provided with apair of upstandingears217 apertured as at 218 for slidably receiving said rods 216. The screen214 is preferably attached to said :trame 213 by a supporting member 219extending around the perimeter of said-frame and provided with aninturned edge 220 Vor engaging saidscreen. The outer tree end of saidshaft 208 terminates ina head 211 for rotating said shaft.Manipulationof said head 211 to rotate said shaft will move said screen214 toward or away from the scanning device to any desired adjustedposition. The operation of the system L Starting at the sending stationA with is as fol- `the switch 176 closed (similar switch176a at thereceiving stationV also being closed) and the bulb of the illuminatingdevice 12, lit, the object or person X whose image is toA be transmittedis placed in front of the shutter 13. This object or person can beproperly positioned by observing the mirror 200. This mirror ispreferably so tiltedthat a person seeing his image centrally in themirror, is properly stationed with respect t0 the scanning device. Theproper position is centrally 'of the opening 7 5in the lamp 12.

The shutters 13 at the sending station and the shutter 13ay at thereceiving station will reciprocate in synchronism. Thus when coil 16'isenergized and attracts 'itscore to move the crank arm 123 and shutter 13in one direction, coil 16a is also energized, (said coils beingconnected in series) and attracts its core to move crank arm 1230; andshutter 13a. in the same direction. When the cir'- cuit is broken attheend of the stroke, both coils are deenergized and springs 150, 150mretract cores 127 127m respectively to move shutters 13, 13a in theopposite direction. The springs150,150a may be adjusted and so may therheostats 20,206; to ensurea proper synchronization oi the two shutters.

As the shutter 13 of scanning device 10 reciprocates, the only lightthatcan pass from the lampf 12` to the object X is light that passesthru the lamp casing,'the screen 11-and the shutter 13. The light passesthru y opening 75 in the lamp. Light may pass thru the narrow slits 71in the screen 11. But only the light that can penetrate the slit 112which is disposed in alignment vwith openings 90, 104 in plates 86, and91 respectively will reach the object X.

The 'shutter member 105, however may be angularly adjusted, and is soadjusted to dispose the slit 112 therein at a small oblique angle withrespect to slits 71 in the screen. Thusthe slit 112l cuts slits 71 at anangle and light may pass theshutter only Where these slits aresuperimposed. TheV pinhead, can be penetrated by light'rom the l' lamp12 at any one time. The thickness of the laminated strips 691spreferably such that each strip may entirely cover the. obliquey slit112. Thus theslit 112 can at no time overlap any parts ofV two adjacentslits 71.

When the shutter 13 is moved, t-he slit 112 moves across the face oi thelaminated member 68. Supposing the shutter 13 to move to the. left,looking at Fig. 2, and the slit 112 so adjusted that its bottom portionis further to the lett than the top portion, it will be apparent thatthe slit 112 will cross a slit 71 at its bottom portion first and thatthis overlapping portion will gradually move up said slit 71 as shown atYeand Y1 respectively in Fig. 9. The last point of overlapping will thusbe when the top portion of slit 112 crosses the top portion of slit 71as seenat Y2 in Fig. 9. Thus the penetrating portion or the illuminatedspot has travelled in a vertical line from bottom to top.

'As soon as the bottom portion of said slit 112 overlaps the bottomportions of the next slit 71 the illuminated spot travels up an adjacentline. And thus the movement of the shutter causes a single beam orpencil of light to traverse the object X i'n a number of straight linesin rapid succession from the right to the left.

Upon return movement of the shutter (from left to right)v the topportion of the slit 112 first overlaps the top of the slit 71, and theoverlapping portion travels'down` the slit 71. In' this manner, atravelling beam of. light travelling down adjacent vertical lines inrapid succession is produced, and this beam also traverses the obj ectX. The speed of movement of the shutter is so regulated that the obj ectX seems to be entirely illuminated, altho Vat any one instant of timethere is really only one spot on the Whole object which receives lightfrom the lamp 12.

The room where the object X is located is preferably darkened somewhatso as to show up the illuminated object. A background may be providedfor the object X to complete the picture to be transmitted. Thephotoelectric -cell 25 which is positioned on casing wall 46, as is wellknown, is provided with a light sensitive portion. This portion will besensitive to each spot of the object X which is illuminated at any oneinstant. The current in a photoelectric cell, as is also well known',varies in accordance with the intensity of light reflected on the lightsensitive portion. Thus the current in the cell 25 varies as the shuttermoves in accordance with the brightness of the spot on the body X whichVis illuminated at any onetime.

When a dark portion of X is illuminated Y to the neon tubeBO which is inseries circuit with the amplifier 26, and therefore takes the samerelative current as the photoelectric cell.

in the cell 25. As is well known, the brightness of a neon depends uponand varies with the current passing therethru. rIhis Vtube is sensitiveto very rapid lchanges and thus light in casing 47 therefore variesrapidly in accordance to the brightness of the illuminated portions ofobject X.

Since the shutters 13 and 13a are insynchronism, a proper adjustmentofthe slit 112er. in said shutter 13a, and proper adjustments of thescreensV 11, 11a; by turning adjustment rods 77, 7 7 a respectively,will cause a beam of light to pass thru the shutter 13a in a positionwith respect to screen 11a corresponding to the position of the spotilluminating object X at the same instant of time. This beam is thrownin screen 213 which may be adjusted for proper focal distance determinedby the lens 201 thru which the beam must pass.

The beam passing thru shutter 13a also traverses the screen 213 in anumber of vertical adjacent lines in rapid succession, in synchronismwith the beam traversing the object X. The intensity of this beam at aninstant depends upon the brightness of the neon tube 30. The brightnessof any one spot of thel screen213 illuminated by the bea-m at anyinstant is therefore of equal intensity as on equivalent spot on' objectX, which is at that instant also beingv illuminated.l Since theilluminated spots on the screen travels very fast, the illusion is thatthe entire screen is illuminated at once, and since thedifferentportions of the screen are bright or dark in accordance with equivalentportions of the object X, a complete picture of the object is presentedon the screen.

It will be understood that by properly adjusting the speed of thereciprocating shutters, pictures of moving objects may likewise betransmitted.

It will be further noted that the images may in similar manner betransmitted by radio broadcasting and reception.

It will be noted that the area of the screen traversed by the shuttermay be increased either by increasing the heights of the screen andshutter or by increasing the width of the screen and the stroke of theshutter. The area of the subject scanned for a given position of thesubject relative to the screen may thus be increased with comparativelysmall increase in the size of the apparatus and practically no sacrificein compactness thereof. i v

Thus the current passing thru the neon tube varies in accordance withthe variations It will be noted further that by controlling the rate ofreciprocation of the shutter, great frequency of scanning may beobtained in a compact apparatus having comparatively small moving parts.This is of course of particular importance for transmission of rapidlymoving obj ect's,v which in accordance with this invention may beaccomplished by,` small and compact apparatus. A feature of thisinvention is thus seen to reside `in the obtaining of effective scanningover large areas at comparatively high frequencies and effective lightintensities, with a comparatively small size of shutter and screen. Theinvention-thus makes possible television apparatus which is highlypractical since it lends itself to embodiment in small, compact andWieldy apparatus to permit easy handling and installation in the home.

` While in the embodiment herein described the screen and shutter areflat members lying in parallel planes, they may be made curved such ascylindrical, the shutter member being given an oscillatory motion on acurve parallel to the curve of the screen.

It will thus be seen that there is provided device in which the severalobjects of this invention are achieved, and which is well adapted tomeet the conditions of practical use.

l As various possible embodiments might be made of the aboveinvention,'and as various changes-might be made in the embodiment setforth, it is to be understood that all matter y herein set forth orshown inthe accompanying drawings isto be interpreted as illustrativeand not in a limiting sense. o

vHaving thus described my` invention I claim as new and desire to secureby Letters Patent: A f

n 1,. In television apparatus, a scanning de-V vice comprising astationary screenhavlng a plurality of openings and a reciprocatingshutter having an opening adapted to overlap said screenopenings,fduring movement of said shutter.l Y Y 2. In televisionapparatus, a scanning device'comprising a screen having a plurality ofspaced, elongated openings and a reciprocating shutter having a narrowelongated opening adapted to overlap said screen openings duringmovement of said shutter.

3. In television apparatus, a scanning de-v vice comprising a screenhavingl a plurality of spaced, elongated openings and a reciprocatingshutter'having a narrow elongated opening adapted to overlap said screenopenings during movement of said shutter, said shutter opening beingobliquely disposed relative to said screen openings. Y g

4. In television apparatus, a scanning device comprising a screenhavingfaplurality of spaced, elongated openings and a reciprocatingshutter having a narrow, elongated opening adapted to overlap saidscreenopenings during movement of said shutter, said los shutter opening beingobliquely disposed relative to said screen openings, and means forvarying the angle of said shut-ter opening.

5. In television apparatus, a scanning device comprising a screen havinga plurality of spaced, elongated openings, a reciprocating shutterhaving a narrow, elongated opening adapted to overlap said screenopenings during movement ol said shutter, said shutter openings beingobliquely disposed relative to said screen openings, and means forvarying the width of said openings.

6. In television apparatus, a. scanning device comprising a screenhaving a plurality of spaced elongated openings, a reciprocatu ingshutter having a narrow elongated opening adapted to overlap said screenopenings during movement of said shutter, said shutter opening beingobliquely disposed relative to said screen openings, means for varyingthe angle of said shutter opening, and means for varying the width ofsaid shutter opening.

7. In a system for transmitting pictures, a scanning device comprising alaminated member and a shutter movable with respect to said member, saidmember comprising a series of parallel plates separated by parallelopenings, said shutter being formed with a narrow slit disposed at anangle to said openings.

8. In a system for transmitting pictures, a scanning device comprising alaminated member and a shutter movable with respect to said member, saidmember comprising a series of parallel plates separated by parallelnarrow openings, said shutter being formed with a narrow slit disposedat an angle to said openings, and means for adjusting the position ofsaid laminated member.

9. In a system for transmitting pictures,

al scanning device comprising a laminated member and a shutter movablewith respect to said member, said member comprising a series of parallelplates separated by parallel, narrow openings, said shutter being formedwith a narrow slit disposed at an angle to said openings, means foradjusting the position of said member and means for adjusting theangular position of said slit.

10. In a system for transmitting pictures,

a scanning device comprising a laminated member and a shutter movablewith respect to said member, said member comprising a series of parallelplates separated by parallel narrow openings, said shutter being formedwith a narrow slit disposed at an angle to said openings, means foradjusting the position of said member, means for adjusting the angularposition of said slit and means for adjusting the width of said slit.11. In television apparatus of the character described, a scanningdevice therefor comprising a member formed with a plurality of spaced,parallel, narrow, elongated openings and means for exposing saidopenings successively, a portion only of each opening being exposed atany one instant, said exposed portion moving along the length of one ofsaid openings and then along the length of the next adjacent openinvz12. In television apparatus of the character described, a scanningdevice therefor comprising a member formed with a plurality of spaced,parallel, narrow, elongated openings, and means for exposing saidopenings successively, a portion only of each open ing being exposed atany one time, said ex posed portion moving along the entire length ofone of said openings and then alongthe length of the next adjacentopening, said exposed portions moving in the same direction in eachopening in the same direction.

13. In a system for transmitting pictures, a sending station and areceiving station, a scanning device lat each station and a means foractuating said devices in synchronism, said meanscomprisingelectromagnetic coils at each station electromagnets associated withsaid coils, and a make and break switch controlling said coils andoperated by the electromagnet at one of said stations only.

14. A scanning device comprising a member provided with a series ofspaced parallel slits and a member movable with respect to said rstmentioned member, and provided with a slit disposed at an angle to saidslits.

15. A scanning device comprising a member provided with a series ofspaced parallel slits, a member movable with respect to said firstmentioned member, and provided with a slit disposed at an angle to saidslits and means for varying the angle of said slit.

In testimony whereof I affix my signature.

LOUIS OSKOW.

